Morgenstern disclosed a vacuum die-casting machine in U.S. Pat. No. 2,864,140.
A vacuum die-casting machine of design similar to that of the Morgenstern machine is described in U.S. Pat. No. 4,476,911 assigned to Machinenfabrik Mueller-Weingarten A.G. of Weingarten, West Germany.
U.S. Pat. No. 4,583,579 of Miki et al. relates to the measuring of temperature and calculation of clearance of a plunger, sleeve and spool bush in a die casting machine, in order to control plunger retraction and determine the presence of abnormal operating conditions.